PreInstall runner: surface installer log on EXE failures (LogFile field)

When the runner runs a Type:MSI install it injects /L*v <log> and tails
that log on failure to show what actually went wrong. Type:EXE installs
had no equivalent - if Setup-OpenText.cmd or any other EXE wrapper
failed, the installlog just showed "Exit code 1 - FAILED" with no clue
what happened inside.

Adds an optional LogFile field to JSON entries. When present on a
Type:EXE entry, the runner:
  - Logs "Installer log: <path>" before launching the installer
  - On failure, tails the last 30 lines of that file into the runner
    log (same pattern as the MSI verbose log scan)

Wired up on the OpenText entry to point at C:\Logs\PreInstall\Setup-
OpenText.log (which Setup-OpenText.ps1 already writes itself). Other
EXE entries can opt in by adding their own LogFile field.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

playbook/preinstall/preinstall.json

@@ -96,6 +96,7 @@
       "Installer": "opentext\\Setup-OpenText.cmd",
       "Type": "EXE",
       "InstallArgs": "",
+      "LogFile": "C:\\Logs\\PreInstall\\Setup-OpenText.log",
       "PCTypes": ["Standard"]
     },
     {

playbook/shopfloor-setup/Shopfloor/00-PreInstall-MachineApps.ps1

@@ -218,6 +218,14 @@ foreach ($app in $config.Applications) {
             if ($app.InstallArgs) {
                 $psi.Arguments = $app.InstallArgs
             }
+            # If the JSON entry specifies a LogFile (per-installer log written by
+            # the EXE itself - e.g. Setup-OpenText.ps1 -> C:\Logs\PreInstall\Setup-
+            # OpenText.log), surface it on failure the same way we surface the
+            # msiexec /L*v verbose log for MSI installs. Lets EXE wrappers actually
+            # report what went wrong inside.
+            if ($app.LogFile) {
+                Write-PreInstallLog "  Installer log: $($app.LogFile)"
+            }
         }
         else {
             Write-PreInstallLog "  Unsupported Type: $($app.Type) - skipping" "ERROR"
@@ -292,6 +300,19 @@ foreach ($app in $config.Applications) {
             }
             else {
                 Write-PreInstallLog "  Exit code $exitCode - FAILED" "ERROR"
+
+                # If the JSON entry specifies a LogFile for an EXE install (e.g.
+                # Setup-OpenText.ps1 writes its own log at C:\Logs\PreInstall\Setup-
+                # OpenText.log), tail it here so the runner log surfaces the actual
+                # cause without us having to dig through C:\Logs manually.
+                if ($app.Type -eq "EXE" -and $app.LogFile -and (Test-Path $app.LogFile)) {
+                    Write-PreInstallLog "  --- last 30 lines of $($app.LogFile) ---"
+                    Get-Content $app.LogFile -Tail 30 -ErrorAction SilentlyContinue | ForEach-Object {
+                        Write-PreInstallLog "    $_"
+                    }
+                    Write-PreInstallLog "  --- end installer log tail ---"
+                }
+
                 # Surface the *meaningful* lines from the verbose msiexec log (not just
                 # the tail, which is rollback/cleanup noise). The actual root-cause lines
                 # are: MSI error notes (Note: 1: <code>), failed action returns (return